gordon



(No Model.)

P. W. GORDON.

CONVERTER. No. 395,434. Patented` Jan. l, 1889.

@jjj N N, PETERS PhuwLnhogmplmvr. Waxhinmm D. C.

FRED. IV. GORDON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO GORDON,STROBEL d LAUREAU, OFSAME PLACE.

CONVERTER.

SPECIFICATION forming part of Letters Patent No. 395,434, dated JanuaryIl, 1889.

Vwhich the following is a specification.

This invention pertains to improvements in converters for treatingmolten metal.

One of my objects is to provide for the elimination of phosphorus fromiron. It may be well to indicate in a general way the chemical reactionstaking place in converters.

vThe effect of the oxidizing-blast is to change the silicon of the ironinto silica, the silica rising and floating upon the iron as slag. Thephosphorus in t-he iron becomes phosphoric acid, and it also rises. Whenthe phosphoric acid joins the heated silicious slag, the phosphoric acidbecomes at once decomposed and the phosphorus returns to the iron.Highlyheated silica is thus seen to be fatal to the proper eliminationof phosphorus. So far as the silica of the slag is concerned its effectupon the phosphoric acid may be avoided by tapping olf the silieiousslag as soon as the desiliconizing process is completed, and thencontinuing the blow for the elimination of the phosphorus; but if thelining of the converter be silicious the phosphoric acid will bedecomposed by this acid lining as soon as the phosphoric acid reachesthe surface of the metal. Hence it is seen that the acid slag and t-heacid lining at the metal line of the converter form obstacles todephosphorization. Snelus hoped to overcome this difficulty by using abasic lining. This was practically a failure, as the silica attached thelime of the lining and dtifst-royod it, making the maintenance of thelining too expensive. The phosphoric acid also attacked the basic'lining, forming probably a phosphate of lime. A basic material maycontain about thirty per cent. of silica' and still take up phosphorusand forni a phosphate; but if the silica be iu excess of thirty percent. such will not be the case. Thus it will be seen that Sneluss planresulted in a lining which became rapidly eroded in satisfying thesilica of the slag, and that the silica of the slag decomposed thephosphoric acid. Thomas and Gilchrist ad- Serial No. 171.563. (Nomodel.)

vanced the art by employing the basic lining of Snelus in combination`with charges of basic material. The lime addition was in sufficientquantity to satisfy the silica of the slag and thus save the lining, andalso suiiicient to keep the silica of the slag below thirty per cent.The expense of the linings, however, involved in the basic process is inmany localities so great as to more than compensate for the advantagewhich the basic process offers in the utilization of phosphoritic ores.The practical manufacturing question has thus narrowed itself down tot-he cost of non-phosphoritic ores as againstthe cost of dephosphorizingby a basic process.

In my improved converter I use an acid lining; but I cool it at themetal line, so that its effect is neutral, thus forming a dissimilarlining of a single material-in other words, an acid lining with aneutral zone at the metal line. The silicious slag of course does noharm to the acid lining, and this slag may, if desired, be tapped off toavoid its effect on the phosphoric acid during the process ofdephosphorization. I, however, use basic additions, and, instead oftapping .the silicious slag off, the additions may be in quantitiessufficient to keep the excess of silica in the slag down. In practice Ipropose to tap off the slag and then add lime to receive the phosphoricacid and form a phosphate which is also to be tapped off.

During the blowing process a violent eruptive ebullition takes place inthe converter, and it is evident that if the phosphoric thrown againstthe silicious roof of the converter the phosphoric acid will bedecomposed and the phosphorus return to the iron. I avoid these evils bytwo different plans. One is to cool the roof of the converter below thetemperature at which the silicious lining' can do harm; the other is todispense entirely with the roof of the converter. The latter type ofconverter forms the subj ect-matter of another application for a patent,and will not be described in detail here.

In the roofed convert-erI use a neutral material for the roof 5 but itis evident that the splashings of slag will soon give this neutralmaterial an adhering coating of silcious slag,

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so that in course oi time it becomes in fact an acid roof or basic fromsplashings oi' basic slag' formed by basic additions.

It is a commonly-accepted theory that phosphoric acid is formed at oncewhen the oxygen of the blast meets the phosphorus ot' the iron, and itis known that heated silica decomposes phosphoric acid. A tuyere-openingconsisting of a mere opening in the converterwall would then beproductive in forming phosphoric acid immediately at its mouth, andifthe wall be silicious then the decomposition of the phosphoric acidtakes place at once, even it the formation of the phosphoric acid be notthereby prevented. A tuyere consisting of a mere opening in thesilicious wall is 'thus seen to be an. obstacle tothe dephosphorizingprocess and to be itself subjected to erosion. The upward currents areparticularly directed upward 'along the lining of the converter, and itfollows that the mere wall-port tor the tuyere presents a most unhappycombination of means for forming phosphoric acid and means tor at oncedecomposing phosphoric acid as it moves upward along the lining'.

My invention meets these evils byprotruding the tuyere bodily into themetal, so as to avoid the strong upward currents of phosphoric acidagainst the acid lining. A tuyere protruding from the wall ot' aconverter inward into the metal would, it of acid material, avoid theeil-'feet ot'the action ot the silicious wall by causing the currents topass :farther away from the wall; but the mouth of the tuyere, afterall, presents an acid decomposing agent directly at the point where thephosphoric acid is said to be formed. Hence a protruding acid tuyere isnot by any means perfect. It the tuyere be ol' basic material, then wemust tace the problem of the juncture between a basic tuyere and an acidwall. There would be a destructive antagonism at this juncture. Silicateof lime would be formed as the result ot' the contact of the acid andbase, and the tuyere junct-ure would be destroyed. Hence the material ofthe tuyere must be neutral in order that it may not serve to decomposethe phosphoric acid when formed and Ain order that it may not causedestruction at its juncture with the acid lining, the latterconsideration calling for a tuyere which shall at least be neutral atits point ot juncture with the acid lining. The neutral tuyere may beformed oit iron or of magnesia or bauxite. M agnesi a is, chemicallyconsidered, a basic material; but .in practice .it is found that it isacted on by the silica very slightly, and thus becomes, in practice, aneutral material.

The practical construction oli' tuyeres of neutral material is a mattei':involving much difficulty in the present state ot' the art. Hence Iprefer to employ a basic tu yere and avoid joints at the acid lining.

A basic tuyere may be vl'ormed el' dolomite, vand the juncture with theacid lining may be avoided by dipping it into the material from above.My invention therefore has reference to a converter havingits acidlining cooled at the metal line to avoid its eft'ect upon phosphoricacid and to avoid the effect upon it of basic slag; of a neutralcomforter-hood to avoid the eili'cct olf an acid-lined hood upon thesplashii'igs ot the phosphoritic slag; ci' a cooled hood to avoid theet't'ect upon the phosphoritic slag of silicious splashings adhering tothe hood; ot' a tuyere protruding into the metal and discharging itsoxygen away from the acid lining of the converter; to avoid the evilsdue to the VFormation ot' phosphoric acid in immediate proximity to theacid lining; to a neutral or basic tuyere dipping into an acid-linedvessel :tree trom juncture with the acid lining; to avoid thedestruction resulting from the combination.` ot' an acid and a base, andto details ot' construction herein more fully explained.

l illustrate my invention in the accompanyin g drawings, in which-Figure l is a vertical section through a iixcd converter, and Fig. 2 avertical section through a portion ot the same at the line X of Fig. l.

In the drawin gs, A indicates the bowl of the converter; B, the acidlining thereof; C, the molten metal therein; D, the top ot" the moltenmetal, spoken of. herein as the metal line; E, that portion ot theconverter-lining which is contiguous to the metal line; F, a tuyereformed ot' basic material and dippinginto the molten met-al over theedge ot' the bowl; G, the blast-pipe to which the tuyere structure ishinged; H, dotted lines indicating the position of the tuyere structurewhen swung backward; J, a contracted iron hood over the bowl ot theconverter; K, a watertight trough around the outside ot' the portion Eof the converter-lining; L, a hole through the converter-wall above themetal line for tapping oit' the slag; M, a neck across the trough K,forming the slag-passage through the trough; N, a water-pipe around thetop ol? the hood; O, a row oi' jet-holes in the bottom ot said pipe, andP water in the trough.

The pipe N 'is to be connected with a source oi' water-supply, and thetrough K has a discharge-pipe to preventoverfiow. The tuyere is arrangedto be reciprocated into and out ot' the metal by means ol' a pneumaticengine involved in the tuyere structure.4 This tuyere structure isinvolved in the subjectmatter oi' an applicatioi'i 'for Letters Patenttiled by me May 22, i885, and will not be herein described in detail.Suffice to say that the structure permits the quick insertion andwithdrawal of a tuyere, so that the time of blow may be accuratelycontrolled and the time ot subjection ot' the tuyere to destruction.materially lessened. The portion E ot' the converter-lining is kept socold by the water, P, that the lining at this point does not act uponthe phosphatic slag and is not acted upon by the basic slag. The watershowering from the pipe N keeps the hood cool and supplies the trough.The hood,

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as a neutral hood, is thus preservechand the slag' which adheres to itsinterior is kept at so low a temperature as to be without evil effect.The trough is ormedby the metal of the hood 4being continued downwardpast the rim of the lining and being joined watertight to the exteriorshell of the converter. The hood also thus 'forms an upwardly-contractedshell for the rim of the lining, whereby the lining is prevented fromrising. The slaghole L is partly in the cool lining and partly in thewater-cooled neck M. The tuyere dips into the top of the metal, and theblast 'trom it will take an upward and inward course away from thelining of the converter. The tuyere connected to the blast-pipe by aconnection over the rim of the vessel, whereby contact between thetuyere and the acid lining of the vessel is avoided.

In the operation of conversion the tuyerc dipped the instant the blast.called for, and the blowing is continued to such point of(lesiliconization as may be desired. cions slag, it' desired, is thentapped oft' and the basic additions added, after which the blow iscontinued until the phosphorus is eliminated, when the phosphatic slagmay be tapped oft. The tuyere may be withdrawn trom Jthe metal at anytime when the blast is not wanted, whereby the tu vere is saved fromunnecessary destruction.

Instead of tappin the silieious slag off preparatory to thedephosphorizing blow, sufficient lime maybe charged in the additions toneutralize the elieet of the silica in the slag.

It has heen proposed to so modify 'furnaces having water-cooled liningsas to adapt them to the Bessemer process of conversion, and it has beenproposcll io place water-coils in the lining` of converters, and it hasbeen proposed 1o inject water above the metal in a converter, and it hasbeen jijiroposed io use an iron converter cooled by water.f To cool the'lining of a converter for the purpose of preserving the lining is anold idea noi at all original with me; but, so far as I know, a converterhas never h eretofore been proposed with an acid lining-zone belowthemctal and with a neutral lining-zone at and above the metal. line,nor am l advised that it has ever been proposwl to dephosphorize in aconverter with dissimilar zones, as herein described b v me, nor, sot'ar as l know, has it ever been proposed io jlnoduee dissimilar zonesin a converter by neutralizing a zone of a-n entirely acid liningl byclioling it to prevent the reactions heretofore mentioned.

It has been proposed to employ aeid tuyeres in convertingsvessels havingacid linings, and it has been proposed to employ neutral tuyeres inconverters havingl either neutral or acid linings, and it has beenpro]`)osed to use basic tuyeres and neutral tuyeres in basic-lined Thesiliconverters, and tuyeres ot various kinds have been arranged inconverters free of Contact with the lining of the vessel; but, so far asI know, I am the first to propose the combination of an acid-linedconverter with basic tuyeres arranged free of contact with the acidlining to prevent the reactions heretofore referred to.

To arrange hoods and plates of metal over metallurgical furnaces andpreserve the saine from destruction by water-cooling has heretofore beenproposed; but, so far as I know, I am the ,first to propose combining anacidlined converter with a neutra-l zone at the metal line and awater-cooled hood over the vessel to prevent the reactions referred to.

I claim as my inventionl. In a dephosphorizing-converter, thecombination of an acid lining-zone below the metal line and a neutrallining-zone at the inet-al line, substantially as and for the purposeset forth.

2. In a depliospliorizing-converter, the combination of an acidlining-zone below the metal line and a neutral lining-zinie extendingfrom the top of t-he acid zone upward to or above the slag,substantially as and for the purpose set forth. Y

3. In a dephosphorizii1g-converter, the combination of an acidlining-zone below the metal line, a neutralized acid lining-zone at themetal line, and a cooling-channel in the neutral zone of the lining,substantially as and for the purpose set forth.

4s. In a dephosphorizing-converter, the combination ot an acidlining-zone below the metal line, a neutralized acid lining-zone atthemetal line, a cooling-channel in the neutral zone of the lining, a hoodof neutral material reaching upward from the neutralized lining-zone,and means for distributing a cool* in g agent contiguous but exterior tothe splashreceiving surface of the hood, substantially as and for thepurpose set forth.

In a converter, the combination of a converting-vessel, an acid liningtherefor, and a tuyore formed of basic material and disposed free ofcontacttherewith, substantially as and for the purpose set forth.

In a converter, the combination of a convverling-vessel having a metalshell, an acid lining therelfor, a hood joining said shell at about themetal line ol' the converter and converging upward to a top opening, anannular sl1o\\\'ci.-pipe at the top olf the hood, and a trough at thefoot otl the hood around the lining at the metal line, substantially asand for the purpose set forth.

FRED. W. GORDON.

\Vitnesses:

EDWARD B. FULLER'roN, J No. TAYLOR.

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